Inferences are steps in reasoning, moving from premises to logical
consequences; etymologically, the word infer means to "carry forward".
Inference is theoretically traditionally divided into deduction and induction,
a distinction that in Europe dates at least to Aristotle (300s BCE). Deduction
is inference deriving logical conclusions from premises known or assumed to be
true, with the laws of valid inference being studied in logic. Induction is
inference from particular evidence to a universal conclusion. A third type of
inference is sometimes distinguished, notably by Charles Sanders Peirce,
contradistinguishing abduction from induction.
Various fields study how inference is done in practice. Human inference (i.e.